Blindness and Brain Plasticity in Navigation and Object Perception.
The book, Blindness and Brain Plasticity in Navigation and Object Perception, edited by John J. Rieser, Daniel H. Ashmead, Ford F. Ebner, and Anne L. Corn, emerged as the outcome of a workshop organized by Vanderbilt University in Nashville, Tennessee, with funding from the National Eye Institute, National Instititues of Health, and other sources, that explored the connections among the topics of blindness, animal models of brain plasticity (the degree to which the organization of the brain is amenable to change as a result of experience), human brain imaging, cognitive science, and rehabilitation engineering. This workshop brought together scientists from such diverse fields as physiology, psychology, vision science, engineering, education, and rehabilitation, with backgrounds in basic, cognitive, developmental, and applied science. The presenters of that workshop each contributed chapters to this book. According to the editors, the aim of the workshop and this subsequent publication is to explore "how perception, knowledge, and action come to be coupled together in the absence of vision." The chapters discuss the implications of the findings of basic brain sciences that demonstrate brain plasticity with findings from the cognitive and developmental sciences showing cognitive limitations, individual differences, and developmental differences among people who are blind. The publication attempts to identify where further research is needed and to inspire others to focus on the research problems raised. In my opinion, the book meets this goal admirably. It does not seek to provide answers so much as to raise questions, and it raises many, often elegantly.
Various chapters explore the evidence for cortical remapping (the recruitment of the visual cortex of blind people for storing nonvisual input); the impact of visual deprivation on spatial orientation; the use of sound and tactile information to substitute for vision; and the possible differences in tactile discrimination, echolocation, and spatial orientation abilities among individuals who are blind, including those with early- and late-onset blindness. The book raises questions concerning the possible benefits of cortical remapping and ways in which remapping may be encouraged, facilitated, or enhanced. The potential for the use of other sensory input for visual substitution in performing various activities of daily living, including wayfinding and spatial orientation tasks, is queried. The potential for the development of visual substitution systems is also explored.
ISSUES AND RELATED QUESTIONS FOR AUTHORS AND READERS
The book is organized into four parts, these are entitled Introduction; Experience-dependent Recruitment of Visual Cortex for Non-visual Learning and Development; Perception, Sensory Substitution, and Cognitive Strategies; and From Use-oriented Research to Application. The introductory section consists of two chapters, the second of which is written by Rieser and explains the layout of the book. Rieser explains that he and his fellow editors provided the authors with seven specific issues and the instructions that each chapter must focus on one or more of these issues. Each issue was guided by a specific question involving blindness and brain plasticity. These instructions, then, formed the basis for achieving some degree of coherence to this volume. Chapter 2 also provides the reader with three major issues and related questions to keep in mind when reading the book. These are focused on brain plasticity, developmental and individual differences in cognitive functioning and learning, and sensory integration and sensory substitution. In each case, the reader is encouraged to question the evidence provided, the implications for learning and functioning, and the potential such findings may present for the education and rehabilitation of blind and visually impaired people.
The topic of brain plasticity itself will be novel to most readers, as will some of the constructs and methods presented in the various chapters. Thus, the directions given in the introductory chapter are of value in understanding the overall construction of the book and the arguments put forth. Yet, even with this direction, the book is not always perfectly coherent, and the connection of a few of the chapters to the overall topic of the book is somewhat obscure. A number of the chapters are dense, difficult to understand, and often need to be read a number of times. Having said that, however, this book was designed to present a challenge to the reader since no one from any single discipline would be expected to be familiar with all the constructs and methods covered in this book. It comes as no surprise, then, that such a challenge is encountered from place to place throughout this volume.
GIANT LEAP FORWARD
Although Blindness and Brain Plasticity in Navigation and Object Perception may prove difficult to comprehend at times, it also has the potential of heralding a giant leap forward in our understanding of learning and development, navigation, and object perception among visually impaired people, especially those with early-onset disability. It may prove to be as seminal as the early work of Natalie Barraga was on visual efficiency. At the very least, the book may provide a useful theory for understanding why some blind persons, most notably those with early-onset blindness, use echolocation so effectively while others do not. The possibility of understanding this single concept alone could change the way we understand the learning processes of and the potential for visual substitution in people with visual impairment and blindness.
Steven J. La Grow, Ed.D., professor of rehabilitation, School of Health and Social Services, Massey University, Private bag 11222, Palmerston North, New Zealand; e-mail: <s.j.lagrow@ massey.ac.nz>.
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|Author:||La Grow, Steven J.|
|Publication:||Journal of Visual Impairment & Blindness|
|Article Type:||Book review|
|Date:||Feb 1, 2008|
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